1. Field of the Invention
The present invention relates to the field of structural and building systems and structural components used in such systems, more particularly to strong, multi-purpose, lightweight and easily transportable structural and building systems and components for use in safety netting barrier systems, and in particular, to a perimeter safety netting system that is configurable to provide an easily movable and/or reconfigurable netting assembly atop, inter alia, buildings, and substantially surrounding the periphery thereof, during the building construction process.
2. Background and Description of Related Art
When engaged in dangerous construction situations and the like, the safety of those involved as well as pedestrians, bystanders or others in the vicinity may depend on maintaining a safety netting system adjacent the work area. In particular, natural forces such as bad weather, e.g., snow, ice, rain, wind, temperature, material conditions, material properties, worker competency, worker capability etc., have for many years caused accidents in the nature of falling debris which risks injury or damage to people and property in the vicinity of e.g., a high rise building construction site. A properly configured safety netting system adjacent and peripherally enclosing the work area in such construction projects significantly reduces the risk of injury or damage. Various safety netting systems for high-rise construction projects and the like have been provided in the past, but their implementation requirements and constraints and lack of ease of use or reconfiguration have been severe limitations in the effectiveness and efficiency of such systems. Specifically, a netting system that is substantially continuous around the periphery of the top of a building, is easily installed, is easily movable or reconfigurable during the construction process to keep pace with, and/or keep ahead of, the building construction, and is strong and lightweight, has not heretofore been available.
Various types of structural components and systems have been developed or used for safety barrier or netting systems. While typically strong, a common problem with structural systems and components for safety barrier systems is that they are heavy, difficult to handle, move or reconfigure and have a relatively high cost. For example, U.S. Pub. No. 2007/0094942 to Dougall et al. discloses a “Safety Barrier for Multi-Storey Buildings” which “has elongated safety barrier panels extending upwards from a first floor level a sufficient height to serve as effective safety barriers during the work for the subsequent floor. The panels are supported at their side edges in tracks along which the panels can slide. The tracks are duplexed (siamesed) so as to link the respective safety modules into a continuous peripheral barrier. The respective panels and tracks are braced and independently supported, permitting the system elements to be ‘walked’ piecemeal up the face of a structure as required during its erection.” Abstract. However, while the Dougall et al. system described in the aforementioned application appears to provide a vertical perimeter barrier at the top of a building under construction, the description indicates that it does so in a very inefficient manner. The vertical panels used in the Dougall et al. system appear from the description to be very large and unwieldy rigid or semi-rigid structures which would appear to be extremely difficult to move or reconfigure as the building under construction progresses vertically as new floors are added. There is no teaching or suggestion in this application of providing easily movable netting support structures so that an entire netting system, including support structure, may be raised to the next highest position without the use of some involved or elaborate mechanism. The Dougall et al. system purports to use “tracks” in which the barrier panels can slide, and thus the barrier panels do not move up the building as an integral unit with the support structure. In fact, “the secured fence panel 24 serves as a guide for the upward sliding of the side tracks 26, as they are hoisted or winched to their new station at the next level.” ¶ 0034. Thus the barrier panels are not fixedly attached to the vertical support structural members. Rather, the vertical support members and barrier panels are separate components which are engaged via slider tracks. The Dougall et al. system thus appears to involve a quite intricate vertical support structure which is guided by the barrier panels themselves, which panels therefore must be extremely rigid, and thus heavy or requiring a substantial amount of material, to perform the guiding function. However, a desirable aspect of a peripheral netting system would remove such requirement for extensive structure rigidly attached to or incorporated into a barrier panel. Ideally, all or a substantial part of the vertical support structure in such a netting system would be slidably engaged with small footprint building mounting brackets so as to minimize the amount of structure required which would appreciably reduce the overall weight of the system. The Dougall et al. system fails to provide such an efficient system because it requires “dual” (i.e., corresponding) slidably engaging rigid members as opposed to a single rigid member which supports the barrier net (on one side of the net) at all times and which is slidably engaged with a small footprint bracket which is rigidly attached to a construction floor slab. The Dougall et al. system is thus too heavy, expensive and cumbersome to satisfy the need for a safety netting or barrier system for optimal use in high-rise building construction projects.
A further example of a heavy, cumbersome system for providing a safety barrier system for high rise construction is the one provided by United Building Supply Company (“UBS”) of New Rochelle, N.Y. offers a “cocoon” system for purported use atop high-rise buildings during construction to prevent debris from falling. See http://www.ubs1.com/protection-systems.html. However, the UBS system is heavy, difficult to handle and is not easily reconfigurable or movable during construction. The UBS system incorporates barrier panel support members which are engaged with vertical support members which appear to be rigidly attached to the building structure, thus requiring a substantial amount of support member structural material. In contrast, the system described and claimed herein operates by, inter alia, eliminating longitudinally (i.e., vertically) interfacing structural net support members which significantly reduces the amount of material required, and hence the cost is reduced and the system described and claimed herein is as a result much easier to handle and reconfigure during the building construction process.
The UBS system is purported to be a “cocoon protection system” which is “designed to protect the leading edge of floors under construction.” See http://www.ubs1.com/protection-systems.html. The UBS protection system purportedly “[c]onsist[s] of vertical panels, solid horizontal flaps, and a secondary safety net, the system is designed to provide fall protection and debris containment at the source. Connecting to the top two most recently constructed floors, the system extends approximately two and a half additional floors, providing protection at the perimeter of both the top and next to be constructed floors. A series of interlocking panels and slider rails, custom designed and fabricated to the building specifications, allow the system to be raised in sequence with construction operations. Handrails are located at each floor elevation, solid decks are provided for access and debris containment at the lower two floors, and a material net with fine debris liner is installed below the system to provide further containment of any small debris.” Id. While the UBS system described in the aforementioned document appears to provide a vertical perimeter barrier at the top of a building under construction, the description indicates that it does so in a very inefficient manner. The vertical panels used in the UBS system appear from the description to be very large and unwieldy rigid or semi-rigid structures which would appear to be extremely difficult to move or reconfigure as the building under construction progresses vertically as new floors are added. There is no teaching or suggestion in this UBS literature of providing easily movable netting support structures so that an entire netting system, including support structure, may be raised to the next highest position without the use of some involved or elaborate mechanism. While the UBS system purports to use “slider rails,” those rails appear to engage with a stationary vertical support structure. The UBS system thus appears to involve a quite intricate vertical support structure which is rigidly attached to a building under construction and requires a very large amount of material. A desirable aspect of a peripheral netting system would remove such requirement for extensive structure rigidly attached to the building. Ideally, all or a substantial part of the vertical support structure in such a netting system would be slidably engaged with small footprint building mounting brackets so as to minimize the amount of structure required which would appreciably reduce the overall weight of the system. The UBS system fails to provide such an efficient system because it requires “dual” (i.e., corresponding) slidably engaging rigid members as opposed to a single rigid member which supports the barrier net at all times and which is slidably engaged with a small footprint bracket which is rigidly attached to a construction floor slab, and thus has this same drawback as the Dougall et al. system discussed above. The UBS website states that the UBS “cocoon” system is patented. However, no such patent or application was located in a search of USPTO or Google Patents databases.
As to the safety aspect with respect to the UBS system, to the extent the panels must be detached for a move or reconfiguration, the precise situation which it is desired to avoid is created, i.e., large structural members are in danger of being dropped to the ground when a large panel is detached for reconfiguration. A barrier netting or protection system which is not detached from the building under construction during moves of the barrier net system would never present the repeating unsafe condition of the UBS system. Regarding efficiency, much more labor and equipment is required for the UBS system than a system which is reconfigurable without detachment from the building under construction. The UBS system essentially requires its own extensive construction project, time after time, as a building progresses upward. A system which is easily movable or reconfigurable as an integral unit with minimal manual labor and equipment, preferably without a crane, and which does not require detachment from the building under construction, and which incorporates a single vertically reconfigurable lightweight, strong, barrier support member is needed by the high-rise construction industry. However, to date, no such system has been provided.
Other prior systems that are directed to debris barriers for high rise construction are lighter weight than the UBS system, but they are disadvantageous in other critical ways. For example, U.S. Pat. No. 4,815,562 to Denny et al. discloses a debris barrier which is rigidly attached to a building structure and uses a meshed netting structure. The barrier of Denny et al. is comprised of a woven flexible mesh netting having a cord longitudinally extending along the top of the netting to form a reinforced border. The top of the netting is clipped to a safety cable so as to vertically suspend a portion of the netting. See, e.g., Abstract. However, there is no teaching in Denny of any adjustability of the netting during the construction process. Nor is there any teaching of a vertical netting system which substantially encloses the periphery of the top of a building under construction. Nor is there any teaching in Denny of a structural support system which itself is vertically adjustable via brackets attached to the floors which are already completed. Nor does Denny et al. describe a system for enclosing the periphery of a building top with a netting system which is easily and efficiently movable or reconfigurable during the building construction process. Nor is there any teaching in Denny et al. of providing a netting system for extending above a completed work area or floor.
U.S. Pat. No. 4,856,615 to Nussbaum discloses a safety netting system which used fixedly mounted guide rails to allow a net to be raised and lowered. Guide rails are provided which are rigidly attached to a building structure and provide a continuous track along which the safety net may be raised or lowered. Col. 5, lines 59-66. However, there is no teaching in Nussbaum of providing a netting system for extending above a completed work area or floor. Nor is there any teaching in this patent of a structural support system which itself is vertically adjustable via brackets attached to the floors which are already completed. Nor is there any teaching in this patent of a vertical netting system which substantially encloses the periphery of a building top.